Multiple objects in array
Any single array can only contain instances of one object. But in a sense, you can, because you can nest arrays. You can have single element arrays; arrays of arrays; the start and end caps of an array can be arrays. That's sometimes useful, but start and end caps won't merge, if that's what you need, and offsets can sometimes be a bit tricky to set up.

One way to get a variety in evenly distributed objects is to use a particle system: here, distributing a Group of objects on the vertices of a 24-vertex mesh circle.



Make a Group of your objects, give the distributing mesh a particle system, and then set it up something like the illustration. (You don't need Physics, or anything like that). If you need to order your objects, you can 'Use Count' to set up repeating sequences.